<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			
			let i = 3 ;
			
			do{
				i++;
				alert(`跑了${i}圈`);
				
			}while(i < 3);
			
		</script>
	</body>
</html>
